Patent Grant
11129766
Robotic hands have a variety of applications in industry as well as the medical field. Robotic arms, hands and fingers of the prior art often incorporate the use of metal, beatings, cables, and pulleys. However, these devices can have issues associated with cost, complexity, speed of operation, dexterity, and safety. Therefore, there is still a need for robotic hand technologies that provide advantages in terms of power consumption, cost, manufacturing efficiency, power, speed, dexterity, safety and control.
The present invention is directed toward apparatuses, systems, techniques, and methods for robotic movement. More specifically, the present invention can be applied to mechanical joints, joints of the extremities and limbs (including knee joints, elbow joints, the neck, ankle joints, and wrist joints) and robotic hands, including exoskeleton type robotic hands. Embodiments can include flexible exoskeleton robotic hands having flexible actuators with force compensating components. Flexible actuators of the present invention can include finger actuators, thumb joint actuators, thumb actuators, and finger spreading actuators. As a specific example, the present invention can be applied in the medical field to patients that have compromised hand movement.
A flexible actuator of the present invention can include a cavity or balloon with a reinforcement band for providing force compensation, defining a threshold activation force. A change in shape of the flexible actuator can be accomplished by the net force on the flexible actuator, wherein deformation takes place when the sum of force generated upon pressurization of the cavity and the external force is greater than the threshold activation force. The working principles of the present invention can be applied to various applications, e.g., a robotic hand.
A robotic hand or exoskeleton hand according to an embodiment of the present invention can include finger actuators that are flexible and have a cavity or balloon, a means for fluid communication with the cavity, and a pressure source for supplying a pressurized fluid to the cavity. Instead of supplying pressure, pressure can be released from the cavity or a vacuum can be applied to remove fluid from the cavity. Reinforcement bands can be provided on one surface of the finger actuator that restricts the expansion of the finger actuator on that surface. This can allow the opposing side of the actuator to expand relative to the bottom surface, creating a curling or grasping effect.
Reinforcement bands can be provided on the flexible actuators to compensate for joint torque in spastic flexed fingers using the threshold activation force of the flexible actuator. This can allow patients suffering from finger spasticity to extend their fingers, and therefore open their hand normally. Meanwhile, expansion of the flexible actuators on a surface can be restricted, causing the opposing side of the actuator to expand relative to the other surface upon finger joint torque compensation, creating a curling or grasping effect.
The finger actuator (i.e., a flexible actuator) can have multiple cavities that are separated widthwise, creating multiple sub-cavities, each spanning the length of the finger actuator. Furthermore, the finger actuator can also have multiple joint-cavities that are separated lengthwise, wherein multiple sub-cavities each contribute to the overall length of the finger actuator. By selectively pressuring specific cavities in each of the actuators, the actuators can be directed to move in different directions and bend at specific locations. Even when multiple sub-cavities are in fluid communication, the spacing between the cavities can promote bending at specific locations.
A structural mesh can be included within the actuators as a support as well as to control the bending or curling motion. The mesh can be impregnated within the actuators or fixed to the surface of the actuators. The pressure supplied to the cavities of the actuators can be regulated using a control valve, such as a solenoid valve. A microcontroller or microprocessor can be provided to control pressure to the cavities and regulate the overall movement of the exoskeleton hand. The microcontroller (or microprocessor) can have angle sensor signals, pressure sensor signals, solenoid valve signals, fluid source on-off signals, and valve position signals as inputs. Inputs to the microcontroller can also include signals from electromyography (EMG) or electroencephalography (EEG) sensors that allow a person to control the exoskeleton flexible hand.
The present invention can be applied in the medical field to assist those who have been disabled. As a specific example, the present invention can be applied in cases of finger spasticity, which is a serious problem for stroke patients. The present invention can assist stroke patients in recovering their hand function. That is, an exoskeleton hand according to the present invention can assist a stroke patient in opening and closing their hands and can be controlled by signals detected from the user's nerve or muscle signals. More complicated gestures such as pinching or lateral grasping can also be performed. After a series of training exercises, muscle strength of stroke patients can be improved and they may go on to perform normal hand functions without assistance.
Embodiments of the present invention include apparatuses, systems, techniques, and methods for robotic hand movement. More specifically, embodiments of the present invention (“embodiments”) can include robotic hands, including exoskeleton type robotic hands. Embodiments can include exoskeleton robotic hands having flexible actuators with force compensating components. Flexible actuators of the present invention can include finger actuators, thumb joint actuators, thumb actuators, and finger spreading actuators. The present invention can be applied, for example, in the medical field for patients that have compromised hand movement.
The finger actuator 401 can have two, or three, or four, or five (or multiple) cavities that are separated widthwise, creating multiple sub-cavities each spanning the length of the finger actuator. An example of this concept can be seen in
The finger actuator 401 can also have two or three (or multiple) joint-cavities 408, 403 that are separated lengthwise (having multiple sub-cavities each contributing to the overall length of the finger actuator) and joints in between, as shown in
The cross-section of the actuators can be spherical, hemispherical, rectangular, square, or a polygon. A structural mesh 400, 402 can be included within the finger actuators, as demonstrated in
The finger actuators, the thumb actuator, the thumb joint actuator, and the finger spreading actuators 820 can be secured to a glove, and the glove can be worn on one's hand. Alternatively, the finger actuators (or any of the actuators) can include an adhesive on their bottom surface. The adhesive can be secured on a hand or a grasping structure, such as the frame of a robotic hand.
The cavities of the actuators can be supplied with pressure using a tube. The tube can also be used to create a vacuum to remove fluid from and collapse the cavities within the actuators. Angle measuring sensors can be provided at one or more places on the actuators (e.g., at the MCP, PIP, CMC, MP, IP and DIP joints) to measure the angle of each joint. In another example as shown in
The exoskeleton flexible hand can be designed with certain objectives in mind. For example, the actuators can be designed to exhibit a straightening force if applied to a spastic hand of a person who has had a stroke. Therefore, when the cavities of the actuators are at ambient pressure, the actuator will apply a straightening force to the hand. This can be accomplished by including elastic filaments within the actuator (not shown) or by purposeful material selection and design. Furthermore, this can be accomplished by the force compensation providing a threshold activation force to the actuators by the reinforcement bands, while the process includes purposeful material selection and design.
The fluid provided to the cavities of the actuators can be a gas or a liquid, and can be recycled or disposable. For example, a compressed gas can be applied by way of a cylinder or compressor. The pressure source can include a pressure regulator prior to the control valve to maintain consistent performance. Specific examples of gasses that can be applied include carbon dioxide, air, and nitrogen. When the cavities are depressurized, these gasses can vent to the atmosphere or be recycled. The gas can also be drawn out of the cavities creating a vacuum using, for example, a plunger or positive displacement pump. Examples of liquids that can be supplied to the actuators include water, hydraulic fluid, and mineral oil.
Pressurizing the actuators and taking joint angle measurements can occur simultaneously and be regulated using a microcontroller (and/or a microprocessor). The microcontroller can be programmed to determine when increasing pressure no longer results in a change in joint angle measurements and the increase in pressurization can be stopped and the pressure maintained. This feature can allow for grasping of object. The microcontroller can be further programmed to determine grasping strength by specifying the amount of pressure injected to the cavities.
The flexible actuators of the present invention can include an embedded elastomer balloon (or cavity) with a reinforcement band. The flexible actuators can have a single cavity or multiple cavities, and certain embodiments can include supporting filaments. The supporting filaments can form a structural mesh. Working principles of a flexible actuator according to the present invention can be seen in
The pre-deformed initial position (or shape) 120 of an unpressurized elastomer balloon 100 is shown in
Herein, Pi represents the pressure in the pressurizing chambers 104, 105, 106, Patm represents the atmospheric pressure, Fth represents the threshold activation force, and F and F represent the external forces 110, 119, wherein F′>F, Fp represents the force generated by the elastomer balloon 100 upon pressurization (i.e. Pi>Patm) of at least one chamber 104, 105, 106, Δx represents the extension created by F and Fp, Δy represents the increase of extension by the increased external force to F′, Δθx represents the bending motion created by F and Fp, and Δθy is the increase in bending motion caused by the increased external force to F′.
Choice of materials for the reinforcement bands can include elastic or inelastic materials (including metal, rubber, nylon, plastics, polyester, and silicon) with a durometer greater than the elastomer balloon 100, or the remaining part of the actuators. Upon force compensation of the reinforcement band, the stress-strain characteristics of the elastomer balloon 100 is converted from the traditional hyper-elastic model to a new linear stress-strain relationship 200, as shown in
The principle of shifting the pre-deformed initial shape of the flexible actuator is depicted in
The finger actuators 401, 409 follow can operate using the principles of the flexible actuators.
In
A spastic hand of stroke patients is shown in
The force compensation of finger joint torque is determined by defining an optimal value of the threshold activation force Fth of the reinforcement band 406, 407, 412. In more detail, the threshold activation force Fth is defined by the balance between the flexural rigidity (EI) of the reinforcement band 406, 407, 412 and the amount of finger joint torque. The dimensions of reinforcement band can be obtained by the moment of inertia and material selection that leads the flexural rigidity to be equal to the finger joint torque. This equalization defines the threshold activation force of the reinforcement band 406, 407, 412 as the calculated flexural rigidity (i.e. Fth=EI=F), while the external force F equals the calculated flexural rigidity, or the finger joints torque as they are in equal relation. Upon pressurizing the finger actuators 401, 409, any Pi larger than Parm is enough to create the force for achieving a bending motion. In mathematical terms, the pressurization force Fp generated upon pressurization of any pressure inlet Pi>Patm can lead to Fth<F+Fp, as Fth=F. Furthermore, the calculated flexural rigidity also defines the threshold activation stress (i.e. σTh) by dividing the calculated flexural rigidity to the area of pressurizing chamber(i.e. σTh=EI/A).
To increase the degree-of-freedom of the exoskeleton flexible hand 300,
Because of the nature of the plurality of connected pressurizing chambers, no mesh support needs to be embedded into the thumb joint actuator 800 for performing the bending or curling action.
Basic components of the whole control unit include a pressure source 307, solenoid valves 308, pressure sensors 311, and at least one micro-controller or microprocessor 309 for processing the control signals and controlling the pressure to the exoskeleton flexible hand. The pressure source 307 for the pressurization of the exoskeleton flexible hand 300 may be a pump, or any disposable or non-disposable compressed medium including, for example, a carbon dioxide bottle, oxygen tank, compressed nitrogen or compressed air. A pressure regulator can be provided to maintain a constant pressure coming from the pressure source 307.
The solenoid valves 308 can be controlled by either the micro-controller or microprocessor 309. The micro-controller or microprocessor 309 determines the activation period of the solenoid valves 308 from electronic signal inputs, which can be bio-signals that are acquired from different parts of the human body. Examples of capturing bio-signals include detecting electromyography (EMG) signals from the forearm muscles. Electrodes can be attached on specific groups of muscles. When the recorded EMG signal amplitude is greater than a defined threshold (e.g., 20% of the amplitude of the maximum voluntary contraction (MVC)), the micro-controller or microprocessor 309 can instruct the solenoid valves 308 to open. Another specific group of muscles can be targeted for switching off the solenoid valves 308 by following the same principles.
The exoskeleton flexible hand can also be controlled by electroencephalogram (EEG) signals from the scalp. Electrodes can be attached around the head to capture the Mu wave signals of the brain. When Mu expression is detected (e.g., a 20% drop from the resting state), the micro-controller or microprocessor 309 can have the solenoid valves 308 open. Following the occurrence of Mu expression, the solenoid valves 308 can be switched off using the same principles.
The solenoid valves 308 can provide a pressure inlet 310 to the exoskeleton flexible hand 300 when instructed to be switched on by the micro-controller or microprocessor 309. Real time pressure values from the pressure sensors 311, and the bending angle 312 of the finger actuators 401, 409 can both be recorded for the control algorithm to determine if the hand is holding an object. If the bending angle remains unchanged after a period of time (e.g., 2 seconds), but the pressure continued to increase in the finger actuators 401, 409, this can indicate to the microcontroller that an object has been grasped. The solenoid valves 308 can then be switched off and pressure maintained. The recording of bio-signals can continue after the solenoid valves 308 are turned off, forming a closed-loop control unit for the exoskeleton flexible hand 300.
The subject invention includes, but is not limited to, the following exemplified embodiments.
A robotic hand, grasping and/or extension apparatus (or an exoskeleton hand) comprising:
a finger actuator that is flexible and having a cavity (or balloon), a length, and a width;
a means for fluid communication with the cavity; and
a pressure source for supplying a pressurized fluid to the cavity (and/or pulling a vacuum to remove the fluid).
The apparatus of Embodiment 101, wherein the finger actuator has a reinforcement band or bands on a bottom surface (impregnated within the structure or attached to its surface) that restricts the expansion of the finger actuator on the bottom surface (allowing the top of the structure to expand relatively and creating a contraction or grasping motion). The reinforcement band or bands can also compensate for joint torque in spastic fingers.
The apparatus of any of Embodiments 101 to 102, wherein the finger actuator has one, or two, or three, or four, or five (or multiple) cavities that are separated widthwise (creating multiple sub-cavities each spanning the length of the finger actuator). Each of the sub-cavities can have its own pressure source such that, for example, a top sub-cavity can be pressurized (and expand) relative to a bottom cavity, causing the finger actuator to curl or grasp.
The apparatus of any of Embodiments 101 to 103, wherein the finger actuator has two or three (or multiple) joint-cavities that are separated lengthwise (having multiple sub-cavities each contributing to the overall length of the finger actuator) having and joints (areas of the actuators where there is no cavity) in between. The joint-cavities can be in fluid communication using independent tubing or through passages in the finger actuator. The joint-cavities can correspond to each of the metacarpophalangeal joint (MCP)—the joint at the base of the finger, the proximal interphalangeal joint (PIP)—the joint in the middle of the finger, and the distal interphalangeal joint (DIP) of each of the index finger, middle finger, ring finger, and small finger (or pinky) of the human hand. In the case of the thumb, the joint-cavities can correspond to each of the Carpometacarpal (CMC) Joint, Metacarpophalangeal (MP) Joint, and Interphalangeal (IP) Joint.
The apparatus of any of Embodiments 101 to 104, wherein the finger actuator includes a structural mesh. The structural mesh can include lengthwise filaments, widthwise filaments, and/or a patterned mesh (such as a net mesh or a double helical mesh).
The apparatus of any of Embodiments 101 to 105, wherein multiple finger actuators are provided corresponding to each of the thumb, index finger, middle finger, ring finger, and pinky finger.
The apparatus of any of Embodiments 101 to 106, further comprising a finger spreading actuator. The finger spreading actuator can be between any two fingers (including, for example, the index finder and middle finger, index and ring finger, etc.).
The apparatus of any of Embodiments 101 to 107, further comprising a thumb joint actuator. The thumb joint actuator can separate the thumb and index finger and also turn the thumb to oppose the fingers. The thumb joint actuator can include a reinforcement band on its bottom. The thumb joint actuator can include multiple cavities including a top layer cavity (or cavities) and a bottom layer cavity (or cavities). The bottom and top cavities can be in fluid communication such that one pressure source can expand the thumb joint actuator and separate the thumb and index finger. In an alternative embodiment, the top and bottom cavities can have separate pressure sources such that the top expands relative to the bottom and causes the thumb to turn and oppose the remaining fingers. The top and bottom cavity each can have a comb-like structure (see
The apparatus of any of Embodiments 101 to 108, wherein the finger actuators and thumb actuator (and, if included, the thumb joint actuator) are secured onto a glove (which can be placed on a human hand).
The apparatus of any of Embodiments 101 to 109, wherein the finger and thumb actuators (and, if included, the thumb joint actuator) include an adhesive on the bottom surface (which can be secured on a hand or grasping structure).
The apparatus of any of Embodiments 101 to 110 wherein the means for fluid communication is a tube.
The apparatus of any of Embodiments 101 to 111, further comprising an angle sensor(s) at one or more places on the finger actuator (e.g., at the MCP, PIP, CMC, MP, IP and DIP joints.) Another angle sensor can be provided to measure the opposition angle of the thumb relative to the remaining fingers.
The apparatus of any of Embodiments 101 to 112, further comprising a valve(s) (e.g. a solenoid valve) for controlling pressure to the cavities (or balloons) of the actuators. This can include the actuators for each of the fingers, the thumb, finger spreading actuators, and the thumb joint actuator.
The apparatus of any of Embodiments 101 to 113, further comprising a microcontroller (or microprocessor) that controls pressure to the cavities. The microcontroller can also have angle sensors as inputs. Inputs to the microcontroller can also include pressure signals, solenoid valves and fluid sources on-off signals, and even signals from electromyography (EMG) or electroencephalography (EEG) sensors.
The apparatus of any of Embodiments 101 to 114, further comprising EMG sensors and/or EEG sensors.
The apparatus of any of Embodiments 101 to 115, wherein the cross-section of the finger actuator is spherical, hemispherical, rectangular, a square, or a polygon.
The apparatus of any of Embodiments 101 to 116, wherein the actuators are in a straight position when its cavities have no pressure (and can provide force to straighten a paralyzed patient's hand).
The apparatus of any of Embodiments 101 to 117, wherein one or more of the actuators have narrowed portions (in which the diameter or thickness of the actuator is less than the rest of the actuator) to promote bending at certain locations and reduce the force required for the actuators to bend (not shown).
The apparatus of any of Embodiments 101 to 118, wherein a reinforcement band is provided internally (e.g. extending through the center of the apparatus as shown in
A method of implementing a robotic hand comprising providing any of the apparatuses of Embodiments 101 to 119.
A flexible actuator with a force compensating component comprising:
a deformable elastomer balloon providing motion upon pressurization;
a reinforcement band that extends along to a portion of the elastomer balloon, wherein the force compensating reinforcing band is to exert the same magnitude of compensating force on the balloon to compensate for the external forces trying to alter the shape of the elastomer balloon, and therefore to restrict the change of position of the elastomer balloon.
The flexible actuator of Embodiment 201, wherein the position of the elastomer balloon changes as soon as the sum of force generated upon pressurization of the elastomer balloon and the external forces are larger than the maximum force that the reinforcement band can provide, defined as the threshold activation force.
The flexible actuator of any of Embodiments 201 to 202, wherein the maximum stress on the reinforcement band is lower than the yield strength, thereby restricting the motion of the elastomer balloon to deform the reinforcement band together in the same direction only elastically but not plastically to assure the ability of returning to pre-deformed initial position or shape.
The flexible actuator of any of Embodiments 201 to 203, wherein the material model of the elastomer balloon is linearized from hyper-elastic to follow the linear stress-strain relationship of the reinforcement band, defined by the Young's modulus of the reinforcement band.
The flexible actuator of any of Embodiments 201 to 204, wherein the reinforcement band is comprised of elastic materials with a durometer higher than the elastomer balloon.
The flexible actuator of any of Embodiments 201 to 205, wherein the materials adopted for the reinforcement band can change shape or stress-strain relationship properties upon temperature variations and can alter the pre-deformed initial position (or shape) of the elastomer balloon to others at unpressurized situation.
The flexible actuator of any of Embodiments 201 to 206, wherein the reinforcement band can be covered by at least one flexible sensors quantifying the motion of the elastomer balloon in terms of any physical quantities.
The flexible actuator of any of Embodiments 201 to 207, wherein the shape of the elastomer balloon and the reinforcement band is arbitrarily designed.
The flexible actuator of any of Embodiments 201 to 208, wherein the inner cavity of the elastomer balloon is divided into at least one isolated chamber for receiving at least one pressure inlet.
The flexible actuator of any of Embodiments 201 to 209, wherein the motion of bending, extension, twisting, or expansion are defined accordingly with the pattern shape of the structural mesh support, or the division of the inner cavity of the elastomer balloon.
The flexible actuator of any of Embodiments 201 to 210, wherein the structural mesh support is inextensible and strain-limiting at the region of the elastomer balloon that adhered to the mesh support.
An exoskeleton flexible hand comprising:
at least one finger actuator corresponding to one human finger, wherein each of the finger actuator comprises at least one flexible actuator corresponding to at least one finger joint on human fingers.
a control unit to manipulate the pressure inlet to at least one finger actuator; and
at least one pressure inlet for the communication between at least one finger actuator and control unit.
The exoskeleton flexible hand of Embodiment 301, wherein five finger actuators cover across at least one finger joint on each of the five human fingers for each of the finger actuators, and wherein at least one pressure inlet is in communication with the finger actuators.
The exoskeleton flexible hand of any of Embodiments 301 to 302, wherein the reinforcement band of the flexible actuator is configured to assist in extending an impaired flexed finger upon depressurization.
The exoskeleton flexible hand of any of Embodiments 301 to 303, wherein five finger actuators are configured to bend towards the reinforcement band upon pressurization to assist in grasping with one's hand.
The exoskeleton flexible hand of any of Embodiments 301 to 304, further including at least one thumb joint actuator that includes at least one flexible actuator.
The exoskeleton flexible hand of any of Embodiments 301 to 305, wherein at least one thumb joint actuator is placed around the thumb joint on the human hand to facilitate the capability of moving in all directions for the thumb.
The exoskeleton flexible hand of any of Embodiments 301 to 306, wherein the five finger actuators and at least one thumb joint actuator are attached to a wearable glove together for full hand function.
The exoskeleton flexible hand of any of Embodiments 301 to 307, wherein the control unit includes a pump, or connection with any disposable or non-disposable compressed medium for the pressurizing source.
The exoskeleton flexible hand of any of Embodiments 301 to 308, wherein the change in bio-signals captured on one's body, e.g. EMG, EEG, etc. can be used as an indicator to control the pressure inlet to the finger actuators.
The exoskeleton flexible hand of any of Embodiments 301 to 309, wherein the control unit has at least one pressure sensor to monitor the pressure inside the finger actuators.
The exoskeleton flexible hand of any of Embodiments 301 to 310, wherein the bending angle of the five finger actuators is detected by the flexible sensors on the reinforcement band of the flexible actuator.
The exoskeleton flexible hand of any of Embodiments 301 to 311, wherein the control algorithms stops the motion of hand grasping or opening by detecting if there is no change in bending angle after a period of time to maintain the finger posture.
A method for implementing a robotic hand comprising:
providing a finger actuator that is flexible and having a cavity (or balloon);
providing a means for fluid communication with the cavity;
attaching the finger actuator to a human finger or like structure (e.g., a robotic hand frame); and
injecting a fluid into (or removing from) the cavity to curl (or straighten) the finger actuator. This can be used, for example, to grasp or release an object.
The method of Embodiment 401, further comprising providing a reinforcement band (or other means to restrict expansion) on a bottom surface (impregnated within the structure or attached to its surface) of the finger actuator, and having the top of the finger actuator expand relative to the bottom of the finger actuator and creating a curling, contracting, or grasping motion.
The method of any of Embodiments 401 to 402, wherein the finger actuator has one, or two, or three, or four, or five (or multiple) cavities that are separated widthwise (creating multiple sub-cavities each spanning the length of the finger actuator). Each of the sub cavities can have its own pressure source such that a top sub-cavity can be pressurized (and expand) relative to a bottom cavity causing the finger actuator to curl or grasp. As seen in
The method of any of Embodiments 401 to 403, wherein the finger actuator has two, or three (or multiple) joint-cavities that are separated lengthwise (having multiple sub-cavities each contributing to the overall length of the finger actuator) and joints in between (see
The method of any of Embodiments 401 to 404, further comprising restricting and/or reinforcing portions of the finger actuator using filaments (e.g., using a structural mesh). A structural mesh can include lengthwise filaments, widthwise filaments, and/or a patterned mesh (such as a net mesh or a double helical mesh).
The method of any of Embodiments 401 to 405, further comprising providing multiple finger actuators corresponding to each of the thumb, index finger, middle finger, ring finger, and pinky finger.
The method of any of Embodiments 401 to 406, further comprising spreading multiple finger actuators. The multiple finger actuators can be spread using a finger spreading actuator between any two fingers.
The method of any of Embodiments 401 to 407, further comprising providing a thumb joint actuator that can spread the thumb from the index finger and also cause the thumb to turn and oppose the fingers. The thumb joint actuator can include a cavity and a reinforcement band on its bottom. The thumb joint actuator can include multiple cavities including a top layer cavity (or cavities) and a bottom layer cavity (or cavities). The bottom and top cavities can be in fluid communication such that one pressure source can expand the thumb joint actuator and separate the thumb and index finger. In an alternative embodiment, the top and bottom cavities can have separate pressure sources such that the top expands relative to the bottom and causes the thumb to turn and oppose the remaining fingers. The top and bottom cavity can each have a comb-like structure and multiple layers (see
The method of any of Embodiments 401 to 408, wherein the finger actuators (and, if included, the thumb joint actuator) are secured onto a glove (which can be placed on a human hand).
The method of any of Embodiments 401 to 409, wherein the finger actuators (and, if provided, the thumb joint actuator) include an adhesive on the bottom surface (which can be secured on a hand or robotic hand frame).
The method of any of Embodiments 401 to 410, wherein the means for fluid communication is a tube.
The method of any of Embodiments 401 to 411, further comprising an angle sensor or sensors at one or more places on the finger actuator (e.g., at the MCP, PIP, CIVIC, MP, IP and DIP joints.) Another angle sensor can be provided to measure the opposition angle of the thumb relative to the remaining fingers.
The method of any of Embodiments 401 to 412, further comprising a valve(s) (e.g. a solenoid valve) for controlling pressure to the cavities (or balloons). This can include the actuators for each of the fingers and the thumb, the thumb joint actuator, and finger spreading actuators.
The method of any of Embodiments 401 to 413, further comprising providing a microcontroller that controls pressure to the cavities. The microcontroller can also have angle sensors as inputs. Inputs to the microcontroller can also include pressure signals, solenoid valves and fluid sources on-off signals, and even signals from electromyography (EMG) or electroencephalography (EEG) sensors.
The method of any of Embodiments 401 to 414, further comprising providing biosignal detectors (e.g. EMG sensors and/or EEG sensors) that are in communication with the microcontroller (or microprocessor) and attached to a user (or patient). The EMG and/or EEG sensors can then be used to control the robotic hand (e.g., via a microcontroller). Specific examples of signals that can be captured using EEG signals include Mu waves.
The method of any of Embodiments 401 to 415, wherein the cross-section of the finger actuator is spherical, hemispherical, rectangular, a square, or a polygon.
The method of any of Embodiments 401 to 416, further comprising providing a gas to the cavities (of the finger actuators, fingers spreading actuators, or thumb actuator) as a pressure source using a valve (e.g. a solenoid valve). The gas can be recycled (drawn in and out of the cavities) using, for example, a plunger or positive displacement pump. The compressed gas can also conic from a compressed gas source (e.g., nitrogen, carbon dioxide, or compressed air) and can be discharged to the atmosphere. The pressure source can include a pressure regulator prior to the control valve to maintain consistent performance.
The method of any of Embodiments 401 to 417, further comprising providing a liquid to the cavities (of the finger actuators, fingers spreading actuators, or thumb actuator) as a pressure source. The liquid can be recycled (drawn in and out of the cavities) using, for example, a plunger or pump. For example, the liquid can be water, hydraulic fluid, or mineral oil.
The method of any of Embodiments 401 to 417, further comprising simultaneously pressurizing a cavity and taking joint angle measurements; determining when increasing pressure no longer results in a change in the joint angle measurement; and stopping the increase in pressure (or maintaining the pressure). This can correspond to when an object has been grasped by the robotic hand. The microcontroller (or microprocessor) can be programmed to determine grasping strength by specifying the amount of pressure injected into the cavities.
A flexible actuator comprising:
an elastomer balloon that is flexible and having a cavity, a length, and a width;
a force compensation component;
a reinforcement band for the force compensating component to provide a threshold activation force to the flexible actuator;
a means for fluid communication with the cavity; and
a pressure source for supplying a fluid to the cavity.
The flexible actuator of Embodiment 501, wherein exoskeleton flexible hand includes multiple flexible actuators that are provided corresponding to each of the thumb, index finger, middle finger, ring finger, and pinky finger.
The flexible actuator of any of Embodiments 501 to 502, wherein increasing the pressure in the cavity and the external force causes the generated force on the flexible actuator to be over the threshold activation force, thereby causing the flexible actuator to change the shape.
The flexible actuator of any of Embodiments 501 to 503, wherein the threshold activation force is adjusted to compensate for the external force that trying to alter the pre-deformed initial shape of the flexible actuator at an unpressurized state.
The flexible actuator of any of Embodiments 501 to 504, wherein the shape of the flexible actuator at an unpressurized state is adjustable when the reinforcement band or bands possess shape memory effect.
The flexible actuator of any of Embodiments 501 to 505, wherein the threshold activation force is related to the selection of materials or the geometry for a reinforcement band.
The flexible actuator of any of Embodiments 501 to 506, wherein deformation of the flexible actuator follows the stress-strain relationship of a reinforcement band, thereby restricting the flexible actuator to elastically change the shape.
The flexible actuator of any of Embodiments 501 to 507, wherein a reinforcing band is an elastic material with a durometer higher than the elastomer balloon.
The flexible actuator of any of Embodiments 501 to 508, wherein the flexible actuator has a flexible angle sensor that quantifies the bending angle of the flexible actuator upon pressurizing the cavity of the flexible actuator.
The flexible actuator of any of Embodiments 501 to 509, wherein the flexible actuator has a flexible strain sensor that quantifies the strain induced on the flexible actuator upon pressurizing the cavity of the flexible actuator.
The flexible actuator of any of Embodiments 501 to 510, wherein the flexible actuator has at least one cavity, or multiple sub-cavities that are separated widthwise and run and overlap lengthwise.
The flexible actuator of any of Embodiments 501 to 511, wherein the flexible actuator has one or multiple joint-cavities that are separated lengthwise;
The flexible actuator of any of Embodiments 501 to 512, wherein the means for securing a flexible actuator to a finger is a glove or adhesive surface.
The flexible actuator of any of Embodiments 501 to 513, wherein the flexible actuators on the exoskeleton flexible hand have a reinforcement band on a bottom surface that compensates for joint torques in spastic flexed fingers.
The flexible actuator of any of Embodiments 501 to 514, wherein the flexible actuator includes a structural mesh.
The flexible actuator of any of Embodiments 501 to 515, wherein the structural mesh is a double helical mesh.
The flexible actuator of any of Embodiments 501 to 516, wherein the exoskeleton flexible hand further provides a thumb joint actuator, and engaging the thumb joint actuator to have the thumb turn and oppose the index finger, middle finger, ring finger, and pinky finger.
The flexible actuator of any of Embodiments 501 to 517, wherein the exoskeleton flexible hand further comprises a finger spreading actuator.
The flexible actuator of any of Embodiments 501 to 518, further comprising a solenoid valve for controlling pressure to the cavity of the flexible actuator.
The flexible actuator of any of Embodiments 501 to 519, further comprising a microcontroller or microprocessor that has angle signals, pressure signals, solenoid valves and fluid sources on-off signals, and electromyography (EMG) or electroencephalography (EEG) signals as inputs.
The flexible actuator of any of Embodiments 501 to 520, wherein the fluid includes a disposable gas or a disposable liquid.
It should be understood that the examples and embodiments described herein are for illustrative purposes only and that various modifications or changes in light thereof will be suggested to persons skilled in the art and are to be included within the spirit and purview of this application.
| Number | Name | Date | Kind |
|---|---|---|---|
| 3981528 | Andorf | Sep 1976 | A |
| 4644938 | Yates | Feb 1987 | A |
| 4733603 | Kukolj | Mar 1988 | A |
| 6447425 | Keller | Sep 2002 | B1 |
| 6901840 | Yatsko | Jun 2005 | B1 |
| 8574178 | Tong et al. | Nov 2013 | B2 |
| 9464642 | Ilievski et al. | Oct 2016 | B2 |
| 9506455 | Mazzeo | Nov 2016 | B2 |
| 9532916 | Tsui et al. | Jan 2017 | B2 |
| 20030110938 | Seto | Jun 2003 | A1 |
| 20080071208 | Voegele et al. | Mar 2008 | A1 |
| 20080167680 | Voegele et al. | Jul 2008 | A1 |
| 20080300692 | Moser | Dec 2008 | A1 |
| 20130253705 | Goldfarb | Sep 2013 | A1 |
| 20150351936 | Mosadegh et al. | Dec 2015 | A1 |
| 20160252110 | Galloway et al. | Sep 2016 | A1 |
| 20170030381 | Shepherd et al. | Feb 2017 | A9 |
| 20170119614 | Yeow | May 2017 | A1 |
| 20180303698 | Wijesundara et al. | Oct 2018 | A1 |
| 20190374422 | Yeow et al. | Dec 2019 | A1 |
| Number | Date | Country |
|---|---|---|
| 1613618 | May 2005 | CN |
| 201194898 | Feb 2009 | CN |
| 103442667 | Dec 2013 | CN |
| 105619397 | Jun 2016 | CN |
| 106309083 | Jan 2017 | CN |
| 106456435 | Feb 2017 | CN |
| 2006-204612 | Aug 2006 | JP |
| 4564788 | Oct 2010 | JP |
| Entry |
|---|
| International Search Report dated Jun. 7, 2018 in International Application No. PCT/CN2018/080804, with its Written Opinion. |
| Office Action dated Oct. 20, 2020 in Chinese Application No. 201810330819.2. |
| Kamper, D.G. et al., “Relative Contributions of Neural Mechanisms Versus Muscle Mechanics in Promoting Finger Extension Deficits Following Stroke”, Muscle & Nerve, Sep. 2003, 28:309-318, Wiley Periodicals, Inc. |
| Kamper, D.G. et al., “Weakness is the Primary Contributor to Finger Impairment in Chronic Stroke”, Arch Phys Med Rehabil, Sep. 2006, 87:1262-1269, American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation. |
| Towles, J.D. et al., “Lack of Hypertonia in Thumb Muscles After Stroke”, J Neurophysiol, Oct. 2010, 104:2139-2146, The American Physiological Society. |
| Number | Date | Country | |
|---|---|---|---|
| 20180296419 A1 | Oct 2018 | US |
